For investigations of pressure distributions on wind tunnel model surfaces with high spatial resolution new experimental techniques, such as Pressure Sensitive Paint (PSP) are required. Using this non- intrusive optical pressure measurement technique, spatial structures and/or rapid temporal or spatial changes of aerodynamic phenomena (transition from laminar to turbulent flow, coherent structures, pitching airfoils in transonic flows with shocks, rotors, test facilities with short run time and different flow temperature etc.) can be investigated. The PSP technique has also expanded from the measurement of steady state pressures to include both periodic and unsteady phenomena to study the instantaneous structure of pressure fields in various areas of fluid mechanics.